Sculpture by starlight

[Big V]

Well the clouds cleared out (sorry Brook) and Adam and I decided that as it was my last night of the Broken Hill trip we should photograph one of the iconic sculptures by starlight. As the moon was not going to rise until just after 11.00pm we were able to get nearly three hours of data for the final night shoot of our star trail theme for the week. Here is my result and Adam will probably add his when he wakes.

[LostDingo2]

Nice image Big V, like the composition but is it just me or do the start trails curve two different directions?

Broken Hill has some good photo opportunities, you did well with this

[Big V]

Yes they do and that is because we were looking west to north. If you look south you get circles, if you look due east or due west you get lines, if you look north you get arcs anywhere else a combination. Hope that explains it.

[Mr Darcy]

I'll add a little to that.
From a viewpoint on Earth, all stars "rotate" around the celestial (Assume this word in the rest of this post) poles.
THe celestial pole is the point in the sky that is directly above the terrestrial pole.

The stars south of the equator appear to go round the South Pole. Those in the Northern Hemisphere go round the North Pole.

This photo straddles the equator, but showing somewhat more of the southern stars than the northern ones. So there is a clear centre to the southern stars, while the northern stars show arcs around the north celestial pole. My guess is that a quite wide lens was used.

In broken Hill, the North Pole is below the horizon, so you will never get complete circle trails from stars in the North showing up in a photo taken from this location.

HTH

[aim54x]

Once again, another stunning photo!!

[adame]

We've definetly had a productive week, thats for sure. My image from the lastnight can be found HERE

[dawesy]

I really like this whole series of images from you guys.

I am interested in the techniques you are using to get these. I have had a couple of quick goes at star trails using long exposures on bulb and had some issue with Noise as you'd expect. I have not had a chance to really try the in camera long exposure noise reduction to see how that helps, but I had not thought about stacking shorter exposures until now.

I have two main questions about this idea, firstly what software are you using to do the stacking? Secondly, to get exposure on the unlit foreground subjects are you lighting them in a couple of exposures, or is it the cumulative effect of all the stacked frames? I would have thought the individual exposures would have little to no detail on those subjects and even stacking wouldn't get the results you have achieved here.

Thanks for any info!

[Big V]

Dawsey, my images are much longer exposures than Adams as he is limited to 30 seconds where I am shooting at 6 minutes or so as a result of this I do not have to paint in the foreground at all. Secondly, we are using an action that we developed for photoshop to take care of the layering of the individual images. Noise is not an issue for my camera - but by combining images you do get a reduction in noise and this is most evident in Adams, if you looked at one of his 30 second exposures and then compared it to the final image you see the benefit of stacking as a tool for noise reduction. For the mathematically minded it is 1 over the square root, meaning the more images you stack the more you reduce the noise. When Adam gets his remote, he will be able to take longer than 30 second exposures but in the mean time this method works well, just means he has to process many more images than me - example 67 for me v 250 for him for last nights shoot, fortunately the action speeds up the layering.

[aim54x]

we are using an action that we developed for photoshop to take care of the layering of the individual images

Can I ask for the method for programming this action???

[fozzie]

Big V - this shot just blows me away The star trails in opposing direction just sets the shot off IMHO, very well done.

fozzie

[Big V]

The action is run as an automated batch process, so you create the action first and then if you wish it to apply the action to many images, you have to then select file, automate, batch and point it to the folder of images that you wish to be stacked..
Thanks all for the kind words..